Graviton-photon oscillation in alternative theories of gravity

In this paper we investigate graviton-photon oscillation in the presence of an external magnetic field in alternative theories of gravity. Whereas the effect of an effective refractive index for the electromagnetic radiation was already considered in the literature, we develop the first approach to take into account the effect of the modification of the predictions for gravitational waves in alternative theories of gravity in the phenomenon of graviton-photon mixing.Comment: V1: 5 pages. V2: 9 pages (new style); clarifications in the discussion included, no physics changes; 3 references added. V3: 10 pages, 4 references added, discussion extended. Version accepted for publication in Classical and Quantum Gravit

Ethnic diversity decreases turnout. Comparative evidence from over 650 elections around the world

Ethnic diversity has been shown to play a significant role in public goods provision, economic growth and government quality, to mention a few. However, we do not know which is the impact of ethnic diversity on turnout. In this article, we determine which dimensions of ethnic diversity affects turnout. To do so, we have gathered data from over 650 parliamentary elections in 102 democracies covering over a fifty-year period. Our models and seven complementary robustness checks show that elections in countries with more fractionalised, more polarised and more concentrated ethnic groups have a significantly and substantially lower turnout.Griffith Business School, Centre for Governance and Public PolicyFull Tex

MYOCARDIAL STRUCTURE AND VASCULARIZATION OF THE HEART VENTRICLE IN HOLOCEPHALI: IMPLICATIONS FOR HEART EVOLUTION

El resumen aparece en el Program & Abstracts of the 10th International Congress of Vertebrate Morphology, Barcelona 2013. Anatomical Record, Volume 296, Special Feature — 1: P-075.It has been classically assumed that the ventricle of the primitive vertebrate heart is composed of spongy myocardium, supplied exclusively by oxygen-poor, luminal blood. This idea is on two facts: (1) extant agnathans have a spongy ventricular myocardium, and (2) in avian and mammalian embryos, the formation of trabeculated myocardium precedes the appearance of compact myocardium. Recently, it has been proposed that, like elasmobranchs, the early gnathostomes possess a fully vascularised ventricle composed of mixed myocardium. We tested this idea by studying the structure and vascularisation of the ventricular myocardium in four holocephalan species of the families Chimaeridae and Rhinochimaeridae. Chimaera monstrosa, Hidrolagus affinis and Harriotta raleighana have a spongy myocardium covered by a thin layer of cardiac muscle. In H. raleighana, the compacta is reduced to an extremely fine rim. In all three species there is a well-developed coronary artery system consisting of subepicardial vessels which give off branches that penetrate the myocardial trabeculae. Rhinochimaera atlantica has no compacta and its ventricular coronary artery system is reduced to subepicardial vessels that do not enter the spongy layer. This report is the first to show that in wild living vertebrates, a coronary artery system supplying the whole myocardium exists in the absence of a well-developed compacta, which supports experimental work that shows that myocardial cell proliferation and coronary vascular growth rely on genetically separated programs. We conclude that the mixed ventricular myocardium is primitive for chondrichthyans, and that the lack of compacta in some holocephalans is a derived character. Moreover our results support the hypotheses that the mixed myocardium is the primitive condition in gnathostomes, and that the absence of a compacta in different actinopterygian taxa is the result of its repeated loss during evolution.Proyecto CGL2010-16417/BOS; Fondos FEDE

The bulbus arteriosus of the holocephalan heart

El resumen aparece en el Program & Abstracts of the 10th International Congress of Vertebrate Morphology, Barcelona 2013.Anatomical Record, Volume 296, Special Feature — 1: P-074.Previous work has shown that the outflow tract of the elasmobranch heart, namely the cardiac portion intercalated between the ventricle and the ventral aorta, does not consist of a single component, the conus arteriosus, as has classically been assumed, but two, the myocardial conus arteriosus and the non-myocardial bulbus arteriosus. From the evolutionary perspective, knowledge of the anatomy of the cardiac outflow tract of the holocephali is important, as they are the sister group of elasmobranchs. Our aim is to describe the cardiac outflow tract of four holocephalan species, two of them, Chimaera monstrosa and Hydrolagus affinis of the family Chimaeridae, and the other two, Harriotta raleighana and Rhinochimaera atlantica, of the family Rhinochimaeridae. The cardiac outflow tract of the four species consisted of a myocardial conus arteriosus, furnished with valves, and a bulbus arteriosus devoid of cardiac muscle. Both the bulbus and conus are tubular in shape. The length of the bulbus relative to the total length of the outflow tract is somewhat smaller in the rhinochimaerids (15%-19%) than in the chimaerids (19%-23%). The bulbus is covered by epicardium and is crossed by the main coronary artery trunks. Histologically, the bulbus is mainly composed of elastin and collagen, and, to a lesser extent, by smooth muscle. This suggests that in holocephalans, the bulbus actively helps to protect the gill vasculature from exposure to high-pressure pulses of blood. Our results prove that the bulbus arteriosus is common to chondrichthyans. In addition, they support the hypothesis that the cardiac outflow tract consisted of a conus arteriosus and a bulbus arteriosus from the beginning of the jawed vertebrate radiation, contributing to our understanding of the morphological changes that have occurred at the arterial pole of the heart in both actinopterygians and sarcopterygians.Proyecto CGL2010-16417/BOS; Fondos FEDE

The Myosin Heavy Chain specific A4.1025 antibody discriminates different cardiac segments in ancient groups of gnathostomes: Morphological and evolutionary implications

El resumen aparece en el Program & Abstracts of the 11th International Congress of Vertebrate Morphology, Washington DC 2016. Anatomical Record, Volume 299, Special Feature: 263.The pan-Myosin Heavy Chain (pan-MyHC) marker MF20 have been reported to show similar, homogeneous signal in the myocardial segments of the heart of teleosts and tetrapods. However, in an ongoing study of the myocardial structure of the dogfish (Scyliorhinus canicula; Chondrichthyes), we observed differential immunostaining of the cardiac segments using another pan-MyHC, the A4.1025 antibody. In order to investigate the relevance of this finding for better understanding of the morphology and evolution of the vertebrate heart, we performed immunohistochemistry, slot blot and western blot in several species of chondrichthyans, actinopterygians and mammals using the above mentioned antibodies. In the dogfish heart, A4.1025 and MF20 specifically recognized MyHC isoforms, although with different degree of affinity. MF20 reactivity was homogeneous and high in all the myocardial segments. However, A4.1025 reactivity was heterogeneous. It was high in the sinus venosus (external layer), atrium and atrioventricular region, low in the ventricle and conus arteriosus, and null in the internal layer of the sinus venosus. A heterogeneous pattern of A4.1025 immunoreactivity was also detected in two other elasmobranchs, a holocephalan, a polypteryform and an acipenseriform. In all of these species, MF20 immunoreactivity was homogeneous. In addition, both markers showed a homogeneous immunoreactivity pattern in teleosts and mammals. Our results indicate that in the hearts of ancient gnathostomes, in all of which a conspicuous conus arteriosus exists, one or more MyHC isoforms with low affinity for A4.1025 show segment-specific distributions. Thus, A4.1025 appears to be an appropriated marker to identify the cardiac segments and their boundaries. We propose that the segmentspecific distribution of MyHC isoforms may generate a particular type of myocardial contractility associated with the presence of a conus arteriosus.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. CGL2014-52356-P, CEIMAR, BIO 203, FEDE

Dos nuevas localizaciones para España de Bulinus truncatus (Audouin, 1827) (Gastropoda: Planorbidae), hospedador intermediario de Schistosomiasis urinaria

Dues noves localitzacions per a Espanya de Bulinus truncatus (Audouin, 1827) (Gastropoda, Planorbidae), hoste intermediari de la Schistosomiasis urinària Durant l’any 2014, els autors han trobat dues noves poblacions de Bulinus truncatus a Espanya. En una, la llacuna de Villena (Alacant), que va ser dessecada al començament del segle XIX, només hi van trobar conquilles, mentre que a l’altra, situada a El Ejido (Almeria), hi van trobar milers d’exemplars vius. L’enclavament de Villena té un gran interès biogeogràfic perquè enllaça les poblacions catalanes amb les andaluses atès que fins ara no se’n coneixia la presència ni a Múrcia ni a la Comunitat Valenciana. La població d’Almeria ha estat objecte d’un estudi conquiliològic i molecular (gen cox1 de l’ADN mitocondrial) que ha revelat un 100% d’homologia amb altres poblacions de B. truncatus les seqüències de les quals estan disponibles al GenBank. La troballa d’Almeria presenta un gran interès davant la possible arribada a Espanya de la Schistosomiasis urinària i l’establiment d’una transmissió autòctona, tal com ja ha succeït en altres països europeus en el passat i recentment.Two new locations in Spain of Bulinus truncatus (Audouin, 1827) (Gastropoda, Planorbidae), intermediate host of urinary Schistosomiasis Two new populations of the planorbid snail species Bulinus truncatus were found in Spain in 2014. The first consisted of shells only, found in the lagoon of Villena (province of Alicante), which had dried up at the beginning of the 19th century. This finding is of important biogeographic interest because it links the presence of this species in northern Catalonia with its detection in southern Andalucia as this species had not been found previously in the regions of Murcia or Valencia. The second population was found in El Ejido (province of Almeria), and thousands of living specimens were found here. This allowed a complete shell characterisation and molecular assessment by means of sequencing the cox1 gene of the mitochondrial DNA genome, which showed 100% homology with sequences of other populations of the same snail species available in the GenBank. The finding of B. truncatus in Almeria is of additional value given the applied importance of this planorbid species as a vector of urinary Schistosomiasis, thus representing a risk of introduction and autochthonous transmission of the disease in Spain, as has occurred in other southern European countries in the past and recently.Durante 2014, los autores han hallado dos nuevas poblaciones de Bulinus truncatus en España. En una de ellas, la laguna de Villena (Alicante), que fue desecada a principios del siglo XIX, sólo se encontraron conchas, mientras que en la otra, que se encuentra en El Ejido (Almería), se hallaron miles de ejemplares vivos. El enclave de Villena tiene un gran interés biogeográfico pues enlaza las poblaciones catalanas con las andaluzas, ya que ni en Murcia ni hasta ahora en la Comunidad Valenciana se conocía su presencia. La población almeriense ha sido objeto de estudio conquiliológico y molecular (gen cox1 del ADN mitocondrial) detectándose un 100% de homología con otras poblaciones de B. truncatus cuyas secuencias ya están disponibles en el GenBank. El hallazgo almeriense es de gran interés por la posible llegada a España de la Schistosomiasis urinaria y establecerse una transmisión autóctona, como ha ocurrido ya en otros países europeos en el pasado y recientemente

Anatomical, histochemical and immunohistochemical characterization of the outflow tract of ray hearts (Rajiformes; Chondrichthyes)

El resumen aparece en el Program & Abstracts of the 11th International Congress of Vertebrate Morphology, Washington DC 2016. Anatomical Record, Volume 299, Special Feature: 264.Recent work has shown that the cardiac outflow tract of sharks and chimaeras does not consist of a single myocardial component, the conus arteriosus, as classically accepted, but two, namely, the myocardial conus arteriosus and the non-myocardial bulbus arteriosus. However, the anatomical composition of the outflow tract of the batoid hearts remains unknown. The present study was designed to fill this gap. The material examined consisted of hearts of two species of rays, namely, the Mediterranean starry ray (Raja asterias) and sandy ray (Leucoraja circularis). They were studied using scanning electron microscopy, and histochemical and inmunohistochemical techniques. In both species, the outflow tract consists of two components, proximal and distal with regard to the ventricle. The proximal component is the conus arteriosus; it is characterized by the presence of compact myocardium in its wall and several transverse rows of pocket-shaped valves at its luminal side. Each valve consists of a leaflet and its supporting sinus. Histologically, the leaflet has two fibrosas, inner and outer, and a middle coat, the spongiosa. The distal component lacks myocardium. Its wall consists of smooth muscle cells, elastic fibers and collagen. Thus, it shows an arterial-like structure. However, it differs from the aorta because it is covered by the epicardium and crossed by coronary arteries. These findings indicate that the distal component is morphologically equivalent to the bulbus arteriosus of sharks and chimaeras. In contrast to foregoing descriptions, the valves of the first transverse row are distally anchored to the bulbus arteriosus and not to the ventral aorta. Our findings give added support to the notion that presence of a bulbus arteriosus at the arterial pole of the heart is common to all chondrichtyans, and not an apomorphy of actinopterygians as classically thought.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. CGL2014-52356-P, CEIMAR, BIO 203, FEDE

Sponges and ascidians control removal of particulate organic nitrogen from coral reef water

10 pages, 5 figures, 5 tables.-- This is HIMB contribution 1199 and SOEST contribution 6596We studied removal rates of plankton and total particulate organic nitrogen (PON) by benthic reef communities from the overlying water in a large experimental flume. The flume was filled with mixtures of coral and coral rubble, and biomass of plankton was measured as water was recirculated over the experimental benthic community. All planktonic particle types, picoplankton, nanoplankton, microplankton, and total PON, decreased in concentration at rates proportional to their biomass. The mean first-order rate constant for the decrease in particle concentration was 96 ± 61 × 10-6 m s-1, corresponding to PON uptake of 10 mmol N m-2 d -1. Synechococcus sp. and heterotrophic bacteria were the major sources of PON. Particulate organic nitrogen removed by rubble and live coral assemblages was directly related to sponge and ascidian biomass (number and area) on the coral and coral rubble. Uptake of PON was about the same as the previously measured uptake of dissolved inorganic nitrogen into these coral reef communities, making it an important flux of nitrogen into the reef. © 2005, by the American Society of Limnology and Oceanography, Inc.Support for this work was provided by a postdoctoral fellowship from the Ministerio de Educación y Cultura (MEC) and a Ramón y Cajal research contract to M.R. This paper was funded in part by NOAA project R/CR-1, which is sponsored by the University of Hawaii Sea Grant College Program, School of Ocean and Earth Science Technology (SOEST), under grant NA 86RG0041. Additional funding was provided by CISNet (NOAA project NA 870A0531) and TransCom (Transfer at Community level) project (REN2002-01631/MAR)Peer Reviewe

Model and methodology for developing empathy: an experience in computer science engineering

Contribution: This article proposes and applies a new systemic 3-D model and a methodology for empathy awareness and development, integrating different partial approaches found in the literature for developing empathy as a transversal competence. Background: Empathy is a competence linked to collaboration and teamwork. Perspective taking (PT) is an important component of empathy and it is key for professionals today. Even though empathy is valued in computer science engineering (CSE) courses, it is not yet fully addressed as an integral part of the training process. Intended Outcomes: Both the model and the methodology are put into practice with a group of first-year CSE students, highlighting the possibilities of the proposal for this course of studies. The experience presented here is an example of a classroom activity in which awareness and PT are addressed, as key components, in relation to the collaborative work toward achieving empathy. Application Design: The methodological proposal is applied to guide educators’ decisions so that they can work on empathy in the classroom. Responses to several standardized and ad-hoc questionnaires by students from two universities are analyzed. Findings: The results revealed low to medium empathy levels in participating students, but a higher perception of their own empathic ability. The proposed methodology allows students to become aware of and develop some initial changes in relation to empathy, particularly in its PT component, through classroom work